[SCSI] scsi_dh: fix reference counting in scsi_dh_activate error path

Commit db422318cbca55168cf965f655471dbf8be82433 ([SCSI] scsi_dh:
propagate SCSI device deletion) introduced a regression where the device
reference is not dropped prior to scsi_dh_activate's early return from
the error path.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@kernel.org # 2.6.38
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

diff --git a/drivers/scsi/device_handler/scsi_dh.c b/drivers/scsi/device_handler/scsi_dh.c
index 564e6ec..0119b81 100644 (file)
--- a/drivers/scsi/device_handler/scsi_dh.c
+++ b/drivers/scsi/device_handler/scsi_dh.c
@@ -394,12 +394,14 @@ int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data)
        unsigned long flags;
        struct scsi_device *sdev;
        struct scsi_device_handler *scsi_dh = NULL;
+       struct device *dev = NULL;
 
        spin_lock_irqsave(q->queue_lock, flags);
        sdev = q->queuedata;
        if (sdev && sdev->scsi_dh_data)
                scsi_dh = sdev->scsi_dh_data->scsi_dh;
-       if (!scsi_dh || !get_device(&sdev->sdev_gendev) ||
+       dev = get_device(&sdev->sdev_gendev);
+       if (!scsi_dh || !dev ||
            sdev->sdev_state == SDEV_CANCEL ||
            sdev->sdev_state == SDEV_DEL)
                err = SCSI_DH_NOSYS;
@@ -410,12 +412,13 @@ int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data)
        if (err) {
                if (fn)
                        fn(data, err);
-               return err;
+               goto out;
        }
 
        if (scsi_dh->activate)
                err = scsi_dh->activate(sdev, fn, data);
-       put_device(&sdev->sdev_gendev);
+out:
+       put_device(dev);
        return err;
 }
 EXPORT_SYMBOL_GPL(scsi_dh_activate);